1. Field of the Invention
The present invention relates generally to circuits for converting phase to voltage, and particularly to a 555 timer-based phase-to-voltage converter that uses a 555 timer operating in a monostable multivibrator mode.
2. Description of the Related Art
Phase-to-voltage converters are widely used in many instrumentation and measurement applications. Over the years many techniques have been developed for converting the phase angles between two pulse trains into voltage. In this regard, phase-to-voltage converters based on the “EXCLUSIVE OR” digital gate and the R-S flip-flop are two of the simplest techniques used. Despite its simplicity, the EXCLUSIVE OR based phase-to-voltage converter can provide a voltage linearly changing with phase angle for phase angles between 0 and π only. While the R-S flip-flop based phase-to-voltage converter can provide a voltage that is linearly changing with the phase angle, by virtue of its operation, it cannot convert very small phase angles approaching 0°, or very large phase angles, approaching 2π.
A simple phase-to-voltage circuit operable over the entire range of phase angles between 0° and 360° would be desirable. Thus, a 555 timer-based phase-to-voltage converter solving the aforementioned problems is proposed.